Preparation And Properties Of Polyurea Anticorrosive Coatings For Repair

Polyurea as a new material that has been gradually developed in recent years,has broad application prospects as an anticorrosive coating for repair due to its advantages such as solvent-free,fast curing,water resistance,chemical resistance,and adjustable performance.Graphine nanoplatelets?GNPs?are widely used in anticorrosive coatings as an excellent filler due to their lamellar structure and excellent physical and chemical properties.In this paper,polyurea resin is used as the matrix and graphine nonoplates are used as the filler to further optimize the performance of the polyurea anticorrosive coating for repair.Firstly,the polyurea matrix was adjusted by amine-terminated ether compound.The compound with a gel time of 37 min,a pencil hardness of 4 H,and an adhesion of3 was selected as the matrix.After that,a polyurea matrix and iron oxide red were used to prepare anticorrosive coatings for repair.The experiments found that the properties of iron oxide red/polyurea composite coatings increased first and then decreased with the increase of filler.At 10 wt.%,the composite coating has the best corrosion resistance.After the salt spray test,the component has a salt spray resistance of 260 h.The electrochemical workstation test shows that the component has a maximum corrosion potential of-0.8826V,the minimum corrosion current is2.608E-5 A/cm².The improvement of the coating's anti-corrosion performance is the effect of iron oxide red particles to isolate and block.In order to compare with ordinary fillers,polyurea and graphine nanoplate was composed.The test found that when the graphine nanoplates was added in an amount of 0.4 wt.%,The coating's salt spray resistance time was 282 h,the corrosion potential was-0.6990 V,and the corrosion current was 2.062E^-5 A/cm².The coupling agent KH550 was used to modify graphine nanoplates and compound with polyurea matrix.When the functionalized graphine nanoplates?f-GNPs?were added in an amount of 0.6 wt.%,The maximum corrosion potential was-0.6428 V,and the minimum corrosion current was 6.286E^-6A/cm²,The anticorrosive mechanism of ink microchips is mainly electrochemical anticorrosion and isolation.The modified graphite microchips have better dispersibility and interface binding force.